In yet another example of long-delayed discovery, it turns out that you can treat a number of filarial diseases, such as elephantiasis or onchocerciasis (river blindness) with tetracycline or doxycycline.

Heedless of the evolutionary imperative to do no unnecessary harm, these parasitic worms cause all kinds of trouble, some of it by a surprising mechanism. They carry Wolbachia, a symbiotic bacteria, and it seems Wolbachia proteins are responsible for most of the inflammatory damage, through an endotoxin-like activity. By the way, Wolbachiais the Chickenman of parasites and extremely interesting in itself.

Antibiotic treatment sterilizes filiarial nematodes, inhibits larval development, and reduces viability of adult worms. I will bet any amount of money that poorly educated doctors (drunken remittance men, etc) in Africa had good results (by accident) using tetracycline on people with filarial disease as far back as the 1950s. It must have happened again and again and again – and since few of those doctors ever went to Harvard, I’ll bet some of them noticed it. There is a good chance that one or two of them actually tried to write up their results, but of course no journal would publish that kind of nonsense.

24 Responses to Beneath Low-Hanging Fruit

Nubian mummies studied in the 1990s were found to contain significant levels of tetracycline; the beer brewed at the time could have been the source.[8] Tetracycline sparked the development of many chemically altered antibiotics, so has proved to be one of the most important discoveries made in the field of antibiotics.[citation needed] It is used to treat many Gram-positive and Gram-negative bacteria.[citation needed] Like some other antibiotics, it is also used in the treatment of acne.

So there’s something keeping medical doctors from noticing low-hanging fruit. From what you’ve seen trawling through the medical literature, is there a common cause behind these cases (besides something generic, like stupidity) or is it something different in each case?

For instance, what kept the respectable people from figuring out what you just wrote in this post?

I try to comment whenever you bring up the topic of low-hanging fruit because hacking this problem would have unbelievable bang for the buck. I mean “unbelievable” in the literal sense, because, by definition, low-hanging fruit discoveries are both easy to make and have payoffs that cannot be anticipated.

Maybe you only see what you’re already looking for. Selection bias, and all. I mean some very smart people failed to notice that the USSR was a nightmare tyranny, and it was right in front of them for 75 years, and they didn’t notice, beacuse they had been trained to look for tyranny on the Right, not the Left. maybe it was something like “antibiotics don’t work on parasites, everyone knows that. If it looks like they work, it must be someting else, coincidence, or an underlying infection.”

In medicine, as in politics – “When the facts don’t fit the theory, change the facts”

Since you don’t state it explicitly in your post, I think it’s worth clarifying that the therapeutic effect of tetracycline on filarial diseases is that it kills the Wolbachia parasites the worms require for reproduction.

As tetracycline is used in combination therapy for malaria, endemic in the same areas as filarial diseases, it wouldn’t have been shocking for someone to figure out its efficacy for the latter by accident. In this case laboratory science established the Wolbachia-link and led to the drug being used in the clinic.

Greg, any thoughts on the hygiene hypothesis, that worm infections protect against allergies and autoimmune disorders?

That’s right, it hits the apicoplast, an organelle acquired via secondary embosymbiosis–originally a bacteria living inside an algae, which in turn started living inside the malaria parasite. As such, it retains ribosomes (the target of tetracycline) similar enough to bacterial ones that are also inhibited.

There’s a similar situation with some antibiotics (like chloramphenicol) that have toxicity issues b/c they inhibit the ribosomes in our mitochondria, which also originated as endosymbiotic bacteria.